BORREGO SPRINGS  The telephone started ringing off the hook at the Anza-Borrego Desert Natural History Association’s Nature Center in Borrego Springs last month, shortly after the group’s newsletter started arriving in mailboxes.

Association members, by the hundreds, were calling as fast as they could to reserve spots for an April 1 hike featuring two very special guests.

Royalty was coming to Borrego Springs, it appeared.

The announcement in the five-time-a-year “Sandpaper” newsletter said Prince William and Kate Middleton would be participating in an April 1 hike hosted by the group:

“We are honored to welcome Prince William and Kate Middleton to Anza-Borrego, as they take time during their California vacation to enjoy a short desert hike with ABDNHA. This unique event offers an exceptionally rare opportunity to be a part of a very small group that will experience Anza-Borrego with both the Duke and Duchess of Cambridge.”

The announcement went on to say that, “for security reasons, the hike location cannot be announced until the time of departure. Meet at the ABDNHA Library at 9 a.m. and then drive as a group to a spot to await the Royal helicopter. This April 1 activity is expected to fill quickly. Bring water, sun hat, and good hiking shoes. No charge; call to reserve.”

And call they did.

“It’s been a funny, funny thing,’ said Ann a volunteer at the nature center who declined to give her last name. “The phone was ringing off the hook. It was a riot how many people believed it.”

The listing, sandwiched in between dozens of other upcoming hikes and events sponsored by the association, was an April Fools Day joke.

Ann said so many people kept calling during the last week of February that volunteers stopped explaining the listing was a fake and simply told them all the spots had been filled.

Exactly whose idea it was to advertise the fake hike is unknown. “There are a lot of people who work on the newsletter and none of them have taken credit yet,” Ann said.

For the record, Prince William, Kate Middleton and their son, Prince George, will not be vacationing in California but are planning an Australia/New Zealand trip next month.